By Elyse Scura, CBC News Ottawa, August 14, 2023
The type of heavy rain that hit Ottawa last week and causes roads and basements to flood could push planners toward a natural solution with a playful name: the sponge city.
More than 75 millimetres of rain was dumped on the nation's capital Thursday afternoon, a deluge so intense it temporarily overwhelmed drainage systems.
...Usman Khan, an urban hydrology expert at York University, said the central issue is that roads, rooftops and parking lots inhibit the water cycle and encourage flooding because excess water can't be absorbed.
..."Introducing green areas like green roofs, rain gardens, vegetated swales can help temporarily hold water in the same way that a sponge does during rain events — and then release it slowly over time."